1. Field of the Invention
The invention relates generally to a method and system for producing ethanol and more particularly to a method and system for producing ethanol using one or more feedstock processing plants located near a feedstock producing or a feedstock storage site and an ethanol producing plant.
2. Description of Related Art
It is known to use a variety of different types of feedstock to produce ethanol. It is also known to utilize a number of different methods for processing feedstock into ethanol. However, each of the different conventional methods suffers from one or more disadvantages, regardless of the type of feedstock used to produce ethanol. For example, conventional methods for producing ethanol require raw, unprocessed feedstock to be transported from the site where the feedstock is produced or stored to a remote processing plant. Transportation of raw, unprocessed feedstock from the site of the feedstock producer to the ethanol producing plant results in substantial equipment, labor, fuel, maintenance and repair costs. More particularly, the transportation of raw, unprocessed feedstock results in an ethanol yield (by weight) of approximately 33% of the feedstock (by weight). In addition, the transportation of raw, unprocessed feedstock results in byproduct at the ethanol producing plant which amounts to approximately 33% (by weight) of the feedstock (by weight). Additional transportation costs, including labor, fuel, maintenance and repair, are incurred in connection with the removal of the byproducts from the ethanol producing plant. Further, conventional methods for producing ethanol require large storage capacities at either or both the site of the feedstock producer and the ethanol producing plant.
It would be desirable, therefore, if a method and system for producing ethanol could be provided that reduces the transportation costs associated with the production of ethanol from feedstock. It would also be desirable if such a method and system could be provided that would reduce the tonnage of feedstock transported from a feedstock provider to an ethanol producer. It would be further desirable if such a method and system could be provided that would produce byproducts that may be left at the site of the feedstock provider to be used as animal feed, animal bedding, compost, biofuel, chemicals, or the like. It would also be desirable if such a method and system could be provided that would produce a non-hazardous material to be transported from the feedstock provider to the ethanol producer. It would also be desirable if such a method and system could be provided that would reduce the storage requirements at an ethanol producing plant. It would be further desirable if such a method and system could be provided that would reduce or eliminate the environmental impact caused by the storage of feedstock, the disposal of byproducts, waste products and waste water, and the transportation of feedstock to an ethanol producing plant. It would be still further desirable if such a method and system could be produced that would reduce the size and cost of an ethanol producing plant and improve the efficiency of such a plant.
It is an object of the present invention to provide a method and system for producing ethanol that reduces the transportation costs associated with the production of ethanol from feedstock. It is also an object of the present invention to provide a method and system that reduces the tonnage of feedstock transported from a feedstock provider to an ethanol producer. It is another object of the present invention to provide a method and system that produces byproducts that may be left at the site of the feedstock provider to be used as animal feed, animal bedding, compost, biofuel, chemicals, or the like. It is still another object of the present invention to provide a method and system that produces a non-hazardous material to be transported from the feedstock provider to the ethanol producer. It is yet another object of the present invention to provide a method and system that reduces the storage requirements at the ethanol producing plant. It is a further object of the present invention to provide a method and system that reduces or eliminates the environmental impact caused by the storage of feedstock, the disposal of byproducts, waste products and waste water, and the transportation of feedstock to an ethanol producing plant. It is still another object of the present invention to provide a method and system that reduces the size and cost of an ethanol producing plant and improves the efficiency of such a plant.
These and other objects of the present invention will become apparent from an examination of the drawings, specification and claims contained herein.
As used, herein, the term “feedstock” shall refer to hard grains, starches, cellulose, hemicellulose and lignocellulosic biomasses such as corn stover, cereal straws, sugarcane bagasse, sawdust and paper pulp, waste materials, biomasses farmed for the sole purpose of producing ethanol such as switchgrass, old and/or poor quality animal feed, animal manure, paper, cardboard and the like. It is provided, however, that the term “feedstock” includes any material or substance that may be used to produce ethanol.
As used herein, the term “sugar water” shall refer to the substance produced by the one or more feedstock processing plants of the preferred embodiments of the present invention. More particularly, the term “sugar water” refers to the mixture of sugar and water produced by the mechanical destruction or grinding, the pretreatment, the liquefaction and the enzymolation of feedstock followed by the separation of wet animal feed. The term “sugar water” also refers to a concentrated form of the substance produced by the previously described process. It is also provided within the scope of the present invention that the term “sugar water” refers to a precursor substance of the concentrated form produced by the process described above. For example, the term “sugar water” may refer to the substance produced by the mechanical destruction or grinding of feedstock, or the term “sugar water” may refer to the substance produced by the mechanical destruction or grinding and the pretreatment of feedstock, or the term “sugar water” may refer to the substance produced by the mechanical destruction or grinding, the pretreatment and the liquefaction and the enzymolation of the feedstock. In a preferred embodiment of the present invention, the term “sugar water” refers to a non-hazardous, liquid-processed water based precursor to ethanol.